How to Wire a Generator in the Breaker Box

How to Wire a Generator in the Breaker Box

A generator can be your friend when the power goes out due to infrastructural issues, storms, rain, or other natural disasters.  And in this guide I will explain how to wire a generator to a breaker box.

Install whole house generator may be tricky. A standby generator is wired to your home's electric system. On the other hand, a portable generator must be connected to the electrical panel via a transfer switch. 

The transfer switch converts the electricity source from the mainline to the generator and vice versa. While some people might argue that you could use a generator with an extended, it is not safe or practical to use it for powering your home. Extensions can be used with portable generators outdoors.

Transfer Switch Benefits

The installation of a transfer switch is required by law when connecting a generator to your home. It is dangerous for your home and the electrical infrastructure if you don't have one. An electrician who is working on the poles could be electrocuted if your generator back feeds. Some of the advantages of utilizing a portable generator with a transfer switch are listed below.

 The transfer switch prevents back-feeding and is therefore safe.

This is an easy way to power your house. You can also connect sump pumps, furnaces, and air conditioner units to your home via the breaker box.

 Power management is made easy by the Transfer Switch. You can turn off the devices that you don't use at any given time (e.g., furnaces, pumps, or ACs).

About Wire Quality

Types of transfer switches

Manual Transfer Switches are a common feature in American homes. They are practical, economical, and necessary. It would help if you manually turned the generator's load from the mainline. There are many models of manual switches that can handle 16-18 circuits simultaneously.


Automatic Transfer Switches

If you want to make the conversion from utility to the generator as easy and painless as possible, an automatic transfer switch is what you need. These switches can be programmed to manage the connections by the instructions. These switches prioritize the relationships that you wish to run first. It can also convert the power back to mainline after a blackout. Some models include the ability to connect to a UPS. Automated transfer switches are used frequently in hospitals, banks and prisons, and police stations.

Interlock Kit

Interlock kits are the most affordable of all the options. Although they are simple to install, they are not allowed in all states. However, there are some situations where they can be used. It can cause serious problems if it back-feeds.

How to Wire a Generator to a Breaker Box Safely

You will need tools

  • Electric Wire
  • Generator Cord
  • Transfer Switch
  • Tool Kit
  • Inlet box
  • Drill Machine

How to Wire a Generator in the Breaker Box - Measure the Wires Required

 We now have a basic understanding of the transfer switches. Let's see how to connect your generator to your home using a transfer switch.

Step 1

Measure the Wires Required - Measure the cables from the generator point to the inlet. This will be the generator cable. It is easily available online, in electric shops, or you could make your own. The second wire must reach the transfer switch via the inlet box. The transfer switch should be installed near your home's central electrical control.

Step 2

Installing the Inlet Box  - Place the inlet box at marked points. It would be necessary to attach it to the wall. A drilling machine is required for this. It can be used to plug in the generator. An important safety tip: Installing a shade over your inlet box will keep it from the sun and rain. An inlet box should be installed on the exterior wall of your house. This is the wall of your home where the electric control panel will be put. You may save money by avoiding lengthy purchasing lengths of wire.

Step 3

Put the Transfer Switch in place. Place the transfer switch in the proper location. Tighten the bolts to properly install the transfer switch. Refer to the transfer switch's instruction manual for further information.

Step 4

Wire the System - Mention the exact type of wire you need in your transfer switch's manual and in your generator. Do not choose any other wire. It should be able to handle the load you plan on putting on it. You must be careful with the color of your wires when wiring. Black wires carry current and should be connected to the black. The green wire is a protective ground. It must be connected with the black connector and the neutral (neutral) to the white connector. You should not be able to handle wires if you aren't comfortable with them.

Step 5

Connect the Circuits to the Transfer Switch If your transfer switch supports circuits, connect them to the primary circuit's appliances. You can also connect the room breaker to the switch. These are complex and technical and require extensive knowledge. These are technical areas that you should have a good grasp of. Do not try to interfere with the wiring. When you're working on the main electrical panel of your home, make sure the main supply is off.

Step 6

Check the Transfer Switch - Now it is time to inspect the transfer switch without turning on the generator. The switch should be turned from the main source to the generator. The lights will turn off if you have correctly installed the button. The installation may have a problem if the lights flicker or fluctuate.

Step 7

Examining the Whole System - Once you have connected the wires and correctly installed the transfer switch, it is now time to inspect the whole system and verify what you have done. Turn on the generator, connect the wires to the outlet box and convert the transfer switch to a generator. Make sure that all circuits are turned off on the transfer switch. You can now congratulate yourself by turning on the indicator light in the transfer switch.


Congratulations! To verify their operation, turn each appliance on one at a time. You should not turn on all the appliances at once as this will overload your generator. When checking your system, remember how you've managed the load. You need to know what the generator can handle. The installation of a transfer switch doesn't mean your generator's capabilities are enhanced.


Inlet boxes should be checked for sparks and smells. Also, inspect the wires and switch for any smells, sparks, or other abnormalities.

Step 8

Professional Inspection - After thoroughly inspecting the setup, you can seek professional advice from an electrician. They will inspect the setup and make sure that every connection is in order. This is vital as it could be a violation of your insurance agreement by making connections.


Although it will be a cost-saving project, installing the transfer switch yourself can prove to be dangerous. Your family, appliances, and entire home are at risk. If you don't know how to manage generators and lay wires, don't do it. If you are working with electricity, we recommend following all safety precautions and calling an electrician immediately.

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